CHAPTER II 

 THE PATTERN OF PROTOPLASM 



1, Protoplasm as a Mixed Crystal 



A crystal is usually composed of similar molecules, .occasionally 

 different molecules in mutual connection can form a crystal, known 

 as a mixed crystal. Molecules capable of forming a mixed crystal 

 are different in their chemical composition, but similar in their arange- 

 ment of polar groups and in their molecular sizes. 



The protoplasm can be regarded as a crystal, but since it is by 

 no means composed of the same molecules, it must be a mixed crystal. 

 If the protoplasm is a mixed crystal, the proteins constituting it 

 must be immunologically identical, if not uniform in chemical compo- 

 sition, since the component proteins should be identical in their arran- 

 ment of polar groups. 



It is generally recognized, however, that there exist several types 

 of immunological different proteins, such as serum-albumin and serum- 

 globulin, in the blood plasm which can be regarded as a pool of 

 a liquid protoplasm. At first sight, this fact may appear to disprove 

 the above concept. Nevertheless, the writer interprets this as being 

 attributable to an artificial separation of protein fractions which 

 are present in the plasm in a state of equilibrium exerting mutual 

 influences to form a definite pattern specific to the plasm ; the arti- 

 ficial separation may destroy the equilibrium to make each fraction 

 reveal its own pattern. 



Sorensen (4) has stated that proteins in biological fluids are never 

 single chemical entities but systems of similar molecules in an equili- 

 brium with each other and with other constituents of the solution, 

 and that proteins isolated by the customary method are not identi- 

 cal with those originally present. Kleczkowski (5) observed that when 

 pairs of proteins are heated, they combine in the initial stages of 

 denaturation to form complexes. If one protein is present in larger 

 amount the complex will not precipitate with antiserum to the minor 

 component. The failure to precipitate with antiserum to the minor 

 component could be reversed by peptic digestion of the major compo- 

 nent. Addition of aniserum to the protein present in larger amount 

 precipitates the entire complex. This fact may indicate that the in- 



